The present invention is directed to a method and apparatus for fulfilling orders and, in particular, to a method and apparatus for sorting items into individual orders for packing and shipping or for picking orders. While the invention is illustrated for use with processing orders in batches, it may be used with waveless picking.
Order fulfillment of orders placed over the Internet must take place within a relatively short period of time in order to be commercially competitive. The same could be said for orders received by phone, facsimile, or by the mail based on catalog or television-based merchandizing. Such order fulfillment is known as E-commerce and places demands on an order fulfillment system to meet such obligations. This is compounded by the fact that E-commerce usually involves a large number of small orders (each containing as few as one item in the order) that are selected from a large number of potential items. Each unique item has a specific inventory identification, known in the industry as a stock-keeping unit (SKU). Each item usually bears an optical code, such as a bar code or radio frequency identification (RFID) tag that identifies the SKU of the item.
Because of the large number of SKUs from which an order may be selected, the inventory warehouse may be very large in footprint. As such, it is common to designate geographic portions of the inventory warehouse to each be picked by an individual picker such that each picker picks only a portion of each order, since each order may be spread out over the entire general footprint of the inventory warehouse. Each picker is directed by a warehouse management system to pick portions of a number of orders using a various picking technology known in the art. It is efficient to have the picker mix several orders in one picking or picked receptacle rather than having multiple receptacles, each bearing one order portion. Also, each order may be contained in a number of picked receptacles if the order contains more than an individual item. However, it is then necessary to subsequently sort the contents of the picked receptacle(s) to the order and to process the items so that they can be packed-out for shipment via courier.